In the health care industry, it is well known that there are many ways by which medication can be administered to a patient. For example, medicine can be either swallowed, inhaled, injected or inserted into a body cavity. When it is necessary for the medicine to be gradually absorbed into the body, suppositories which can be inserted into an appropriate body cavity have been particularly effective.
When suppositories are used, physicians ofttimes use manual applicators to assist in inserting the suppository into the body cavity because they provide a safe, reliable and hygenic means for controlling the insertion of the suppository. Additionally, applicators can be used by the patient as a convenient aide for self-insertion when a physician is not needed. To accomplish their purpose, most applicators typically incorporate a tube which holds the suppository while a plunger is manually advanced through the tube to push the medicine into the cavity. Sometimes, however, manual force on the plunger is inadequate for the accomplishment of the task.
In veterinary medicine, manual pressure is often ineffective because of the uncooperative nature of the particular animal. For example, to prevent an animal from spitting out the medicine, veterinarians use spring loaded applicators to shoot the suppository past the soft-pallet in the animal's throat. The spring driven plunger supplies a quick, forceful thrust to the suppository which propels the medicine into the animal's esophagus before it can be disgorged by the animal. One such spring applicator is disclosed in U.S. Pat. No. 199,849 to Middleditch. This particular applicator comprises a tapered tube with a spring driven plunger positioned inside the tube. Once the plunger is retracted, a clip holds it in position until the suppository is ready to be released. The applicator is then placed in an animal's mouth and the plunger is released to propel the suppository down the animal's throat before it can be regurgitated.
As implied above, it is sometimes desirable to insert suppositories into the body cavity of a human being such as the rectum or the vagina. Although conventional spring applicators may work well for the injection of medicinal suppositories into the mouths of animals, due to the violent nature of the forces that are applied, use of these applicators can be painful or even dangerous when used for anal or vaginal insertion on humans. Consequently, manual applicators, as opposed to spring loaded applicators, have been more often used for inserting suppositories into humans. As an example, U.S. Pat. No. 1,538,678 to Blinn employs a tapered tube similar to Middleditch, except that the plunger is manually operated. Unfortunately, manual applicators are subject to the inexperience of the user. Consequently, the force applied on the plunger can be unpredictable and even ineffective. On the other hand, while the applicators that use a mechanical force are more reliable in providing a predictable result, they tend to propel the suppository with a sudden, peaking force which makes anal insertion uncomfortable and which runs the risk of traumatizing the anal canal.
The present invention recognizes the desirability of a suppository applicator which provides a constant, but gentle force on the plunger in order to minimize the danger of tearing or injuring the rectal wall. The present invention also recognizes that this can be accomplished by mechanical means once the bolus of medicine is placed at the cavity orifice.
In light of the above, the present invention provides a suppository applicator which can be repetitively operated to hygenically insert suppositories into body cavities with consistency. The present invention also provides a mechanical suppository applicator that has a prolonged useful life. Further, the present invention provides an applicator that inserts suppositories into a body cavity with ease under a substantially constant linear force. Additionally, the present invention provides a suppository applicator which is simple to sue, is easily manufactured and is comparatively costeffective.